Tora Sivertsen and Helga Eivindsen

I try to locate the emmigration of moter/child Tora Engina Francesca Sivertsen and Helga Johansen or Eivindsen or Sivertsen. Emmigration took place 1921 (Oct. 27 ??) on Bergensfjord to NY. Tora was born in Vefsn 1895 and Helga was born in Vefsn around 1912-1914. Her grandchildren say she was 7 years old at emmigration. They may have ended up in Douglas, Minnesota. Is there a passengerlist available? Could they be mentioned in the US 1930-cencus?